8 troubleshooting – GE Industrial Solutions Entellisys System User Manual User Manual

Page 46

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Metering

46

4

Figure 4-12 Frequency spectra for currents

A description of the quantities available in the Harmonics Metering screen is given above.

4.8 Troubleshooting

Current reads zero or dashes
• Verify that the Messenger is communicating to the CPU in the System Health screen. See

Monitoring system health on page 179

for more information.

• Verify that the frame and CT ratings are properly configured. This information is available on

the Metering & Waveforms menu. See

Basic configuration on page 35

.

• Verify the current exceeds 1% of CT rating. The system will zero the current if below 1%. To

verify this, trigger a waveform manually. The actual current will be displayed on the
waveform.

Voltage reads zero
• Verify that the circuit breaker has a source for voltage data and that the source has a valid

PT assigned to it by clicking Metering on the Metering & Waveforms screen. See

Basic

configuration on page 35

. Also see

PT Throw-Over on page 99

for more information.

Detailed, Demand, or Advanced metering buttons are grayed out
• Verify that the corresponding option has been assigned to that circuit breaker. See

Options

on page 37

.

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